The Lebanon express. (Lebanon, Linn County, Or.) 1887-1898, 1887-06-17
LEBANON OREGON FRIDAY. JUNE II, 1887


ignite an innammablc mixture. Happily |
invention has not been long behind
necessity, and there are at least half-a-
dozen forms of lamp which are safe |
under current veloeities exceeding three |
thousand feet per minute Everybody
will agree with the conclusion Of the
Royal Commissioners that whilst il
would be uuwise to make a particular
lamp compulsory on the ground that
difficulties might thereby bc thrown IN
the way of introducing improvements
in future. II Is nevertheless desirable
that some control should be exercised in
reference 10 the kind Of lamps to be em-
ployed In coal-mines. and that only those
lamps should be used which are author
lied from time TO time by the Secretary
of State.
Fire-damp. however. is not the most
formidable of the causes of eolliery
explosions. II Is doubtful. indeed.
whether a single one Of the more dis
astrous explosions Of modern times can
be directly and wholly attributed 10 its
action. 1t Is significant that violent
explosions seldom occur nowadays in
very wet pits, although the air in them
frequently contains iire-damp. More
over, when explosions do occur in such
pits they rarely extend over large
area, and the loss Of life from them Is
comparatively small Such catastro-
Plies ms those Of Abercarne, Risca,
Seaham and Pcnygraig. where
hundreds of men aud boys are
killed. and where evidence of the ex-
plosion is to be met with in nearly all
parts Of the pits. almost invariably
happen in dry aud dusty pits. 1t hardly
admits Of question that explosions Of
this kind are dependent upon the pres
ence of this dust. Dust explosions In
f1our-mills have long been known, but
il Is only within the last few years that
the action of finely divided coal-dust in
initiating or propngating colliery ex-
plosion has received much attention.
The atmosphere Of deep dry mine is
always impregnated with more or less
dust IL settles everywhere. not only in
the working places. but in the intake
and haulage roads. II is not only on
the floor. hut hangs from the roof
aud timbcrs. and is heaped up on the
lodges A violent movement of the mir
dislodgcs II in clouds; IL naked flame
be introduced into such cloud IL in
flames with explosive violence and the
concussiou of mir i followed by fresh
clouds If dust through which the flame
is propagated.
| with sudden blaze dirus'd iHfiames The air "
Milton said this of guupowder; it is
even truer of coal-dust.
Now there are many conditions in the
ordinary working Of coal mine which
may occasion these violent movements
II the air, and chief among them Is
the prevalence Of what is techni-
cally known as ''shot-iiring that is,
blasting by means of gunpowder. Gun
powder is used in the mine either for
bringing down the coal or for removing
stone. in order. for example. to make
roads for the passage Of horses. and for
engine planes, etc. A hole is driven or
drilled into the coal or stone. into
which certain quantity Of powder. to-
gether with "A fuse. is introduced. and
the rest of the hole is ''stemmed'' or
'.tamped" Is. filled up with small
stones and earth or. too frequently.
with small coal itself. Tho fuse is ig-
nited and the workmen retire either in
TO a ''refuge hole or round corner
until the blast is made. Occasionally
il happens when the charge of gun
powder is too large, or when 1t Is i'm
perfectly stemmed, or when the rock is
unusually hard, that the powder blows
out the stemming and there is violent
conclusion of air. and from the mouth
Of the drill-hole there issues a flame
the length of which will be greatly
increased If small coal has been
used in the stemming. Indeed. it i:
not necessary for the shot TO be ''blowr
out" to produce either the flame or 3
conclusion Of air sufficient to dislodgt
the inilammable dust. We have here 4
condition of things which may be high
ly dangerous in dusty pits. II has been
proved over and over again that shot
firing has been the immediate precursor
of some of the most disastrous collier,
explosions on record. The influence o
dust in at least propagating an explosion
is now generally recognized by mining
engineers and colliery managers, bu
it is still moot point with som'
whether it is capable of initiating al
explosion or, indeed, of propagating i
in the absence of fire-damp. There is
however, considerable body of evi
, dence TO show that whilst the explosive
} character of dusty atmosphere ma.
be greatly augmented by the presenc
of fire-damp, dust alone may be sufii
: cient to bring about the most disastrou
, explosions. 1t is known that explosion
, have occurred simultaneously with tn
J firing of shots in stone, and certain O
these shots have been fired in dust
+ main intake-road, and ut points wher
| currents of air of over 10000 cubic fee
: per minute were passing. 1t is almos
:. inconceivable, except on the theory c
l the sudden outburst of gas at place
. where It's in the highest degree improt
; able that such outbursts could occur
1 that such air could contain any sensibl
l quantity of fire-damp. The concussio
: of air would certainly dislodge larg
= clouds of dust from the roof and frol
Y the floor, and this once ignited, woul
: cause an explosive wave which woul
g travel throughout the pit or so long q
: the ignition was maintained by fires
| Il, - I,,Sf